Eur. Phys. J. B 58, 361-365 (2007)
https://doi.org/10.1140/epjb/e2007-00239-7

Pressure-induced modifications of crystal and magnetic structure of oxygen deficient La_0.7Sr_0.3MnO_3-d manganites

¹ Frank Laboratory of Neutron Physics, JINR, 141980 Dubna, Russia
² Joint Institute of Solids and Semiconductor Physics, NASB, P. Brovka str. 19, 220072 Minsk, Belarus

Corresponding author: ^a denk@nf.jinr.ru

Received: 28 May 2007
Published online: 14 September 2007

Abstract

The crystal and magnetic structures of the oxygen deficient manganites La_0.7Sr_0.3MnO_3-d (d = 0.15, 0.20) have been studied by means of powder neutron diffraction over the 0–5.2 GPa pressure and 10–290 K temperature ranges. La_0.7Sr_0.3MnO_2.85 exhibits a coexistence of rhombohedral and tetragonal (I4/mcm) crystal structures and below T_g ~ 50 K a spin glass state is formed. La_0.7Sr_0.3MnO_2.80 exhibits a tetragonal (I4/mcm) crystal structure. Below T_g ~ 50 K a phase separated magnetic state is formed, involving coexistence of C-type AFM domains with spin glass domains. In both compounds the crystal structure and magnetic states remain stable upon compression. The factors leading to the formation of different magnetic states in La_0.7Sr_0.3MnO_3-d (d = 0.15, 0.20) and their specific high pressure behavior, contrasting with that of the stoichiometric A_0.5Ba_0.5MnO₃ (A = Nd, Sm) compounds showing pressure-induced suppression of the spin glass state and the appearance of the FM state, are analysed.